As a method of preparing the above-described .alpha.-hydroxycarboxylate, there has been proposed a process in which 8-phenylmenthyl glyoxylate is reacted with an olefin compound in the presence of a Lewis acid to produce an .alpha.-hydroxycarboxylate having a specific absolute configuration [Tetrahedron, Vol. 42, pp. 2993-3001 (1986)].
However, the above process for preparing an optically active compound has drawbacks in that depending upon the absolute configuration of the alcohol moiety in the glyoxylate, there can only be obtained a product having either one absolute configuration and in that the Lewis acid should be used in an amount equimolar to the substrate, i.e., glyoxylate.